1. Field of the Invention
The invention relates to the production of methylene malonate species using a bis(hydroxymethyl) malonate intermediary. The intermediary is subsequently cracked to yield a monomer species.
2. Background
A class of polymerizable compositions of interest includes methylene malonates. Methylene malonates are compounds having the general formula (I):
wherein R and R′ may be the same or different and may represent nearly any substituent or side-chain. Such compounds have been known since 1886 where the formation of diethyl methylene malonate was first demonstrated by W. H. Perkin, Jr. (Perkin, Ber. 19, 1053 (1886)).
Methylene malonate monomers and their associated monomeric and polymeric-based products would be useful in both industrial (including household) and medical applications.
However, while earlier methods for producing methylene malonates have been known for many years, these prior methods suffer significant deficiencies that preclude their use in obtaining commercially viable monomers. Such deficiencies include unwanted polymerization of the monomers during synthesis (e.g., formation of polymers or oligomers or alternative complexes), formation of undesirable side products (e.g., ketals or other latent acid-forming species which impede rapid polymerization), degradation of the product, insufficient and/or low yields, and ineffective and/or poorly functioning monomer product (e.g., poor adhesive characteristics, stability, or other functional characteristics), among other problems. The overall poorer yield, quality, and chemical performance of the monomer products formed by prior methods have impinged on their practical use in the production of the above commercial and industrial products.
Certain co-inventors of the instant application have filed patent applications on improved methods of synthesis of methylene malonates, namely, WO 2012/054616 Synthesis of Methylene Malonates Substantially Free of Impurities, and WO 2012/054633 Synthesis of Methylene Malonates Using Rapid Recovery in the Presence of a Heat Transfer Agent. The synthesis procedures provided therein result in improved yields of heretofore-elusive high quality methylene malonates and other polymerizable compositions.
While the improved methods disclosed in the above-identified patent applications are able to provide the desired methylene malonate monomers, continuous improvements are sought, particularly in the development of methods to provide materials on a commercial scale. Thus, a need exists for improved and/or simplified processes for obtaining methylene malonate and related monomers.